Decorative laminates are well-known articles of commerce which have been produced for many years, and find utility in embossed table tops and patterned wall surfaces among many other uses.
Specialty texturing finishes are the current trend in the high pressure laminating industry. To make such finishes economically; thin, strong embossing sheets are required. Generally, aluminum sheet, with an embossing surface has been used to transfer a like pattern to the surface of a high pressure decorative laminate. These embossed sheets, when used in a standard laminate assembly of embossing sheet, overlay sheet, print sheet, and core sheets, must be about 80 mils thick (0.08 inch), to impress a pattern without flattening under pressure. The laminate is generally about 80 mils thick. As can be seen, the thick embossing sheet can take up to 50% of the room in a laminate assembly.
This problem was partly solved by the embossing sheets described in U.S. Pat. No. 3,648,358, which constituted 0.3 to 4 mil aluminum foil having an embossed, pattern side which was used against the overlay and print sheets, and a resin filled flat back side support surface which was used against the press plate. This embossing sheet, while taking up minimal room in a laminate assembly and being able to resist flattening under pressure, required use of a resin casting operation to fill the foil support surface. Preferably, the method also required degreasing and roughing operations, to improve resin-foil bonding, all of which added substantially to process cost. As can be seen, there is a need for a method of making embossed decorative laminates using an assembly contining thin, patterned embossing sheets that are inexpensively supported against flattening under pressure.